US-based exchange operator Nasdaq OMX Group said it would repurchase 22.8 million of its shares, or about 11.5 per cent of the total outstanding, from Borse Dubai for $497 million.

The buyback will be funded by a coinciding $370 million bond sale, the bourse said.

The transatlantic exchange company said it agreed to a price of $21.82 per share, compared with a closing price of $22.53 on Wednesday. Trading in the shares was halted Thursday morning.

The sale reduces Borse Dubai's stake in Nasdaq OMX by more than half, and will help Borse Dubai meet its debt obligations, Nasdaq OMX said.

Borse Dubai has sold about half of its stake in Nasdaq OMX, raising $672 million towards the refinancing of a $2.45 billion loan maturing in February, said a top official.

The move 'allows us to be opportunistic and accelerate our share repurchase plans while delivering significant accretion to our shareholders,' Nasdaq OMX chief executive Robert Greifeld said in a statement.

'The financing gives us sufficient capacity to fund the buyback while maintaining strategic and operational flexibility,' he added.-Reuters